I'm searching for an application to find duplicate images.

In my Linux days, there was a nice Gtk+ application which I could provide some folders and which would list all duplicate images based on some algorithm to determine image-equality (It could detect duplicate images even if one image had a lower resolution or was color shifted) It was also possible to modify the threshold to prevent false-positives.

So far, I found nothing for Mac OS X which could do this.

Nice GUI is a plus.